9.2 Earthquake and Tsunami Anniversary

Earthquake

At 5:36 p.m., 50 years ago, the largest earthquake ever recorded in North America (and second-largest ever recorded in the world) struck Alaska’s Prince William Sound. Today marks the anniversary of the 9.2 Great Alaska Earthquake and the tsunami that followed.

The evening quake reportedly shook the ground for four to five minutes. It spawned landslides in Alaska, which actually caused a lot of the damage in Anchorage, 75 miles away from the epicenter. The 9.2 temblor also created tsunamis that resulted in deaths and damage along the coasts in Alaska, Canada, Oregon and California, as well as Hawaii.

Life magazine described the quake as 2,000 times the mightiest nuclear bomb ever detonated. In Alaska, which had only been a state for five years, there were not a lot of deaths caused by the temblor itself. Many buildings were leveled and portions of the Alaskan coastline were either dropped or lifted 10 to 30 feet.

The shaking was only the start. Like recent examples in Japan and Indonesia, it was the ensuing walls of water that wreaked havoc. According to the Anchorage Daily News, walls of water up to 40 feet high smashed villages.  A reported 90-foot-high wave hit one area.

A tsunami is not really one wave. It is a series of them that can be spread over a period of time. In the Indonesia tsunami, people ventured out after the first wave only to be hit by a second one.

The Alaskan 1964 quake was felt down in Washington State, where the Space Needle visible swayed. The subsequent tsunamis were measured as far away as Florida – yes, Florida! Reportedly, water levels shifted in 47 of the United States from the Alaska quake.

The further away from the epicenter the more warning that can be given to go to high ground because a tsunami is possibly en route. Near the epicenter, it can take minutes before the first wave strikes. When the quake is in Japan, the tsunami might not hit the West Coast of North America for 12 or more hours. In 1964, the tsunami from the Alaskan quake did hit Crescent City, California, until the next day.

In the 50 ensuing years, a lot has changed to protect as best as possible from future temblors and their aftermath. Alaska and the U.S. Geological Survey have quake monitoring systems, building codes have changed (particularly since California quakes in Sylmar in 1971 and Northridge in 1994). There are also quake warning systems that have been tested (including in the Los Angeles area earthquake last week), but not developed on a broad scale.

On the waterfront, the quake lead to the formation of what is now called the National Tsunami Warning Center, which is run by the National Oceanic and Atmospheric Administration.

There are a series of events planned in Alaska to mark the 50th anniversary. Church bells throughout the state will sound marking the exact time. There will also be statewide earthquake and tsunami drills to prepare residents for the inevitable next Alaska earthquake and tsunami.

By Dyanne Weiss

Sources:
Anchorage Daily News
Anchorage Daily News
U.S. Geological Survey
National Geographic
Emergency Management
Fox News
The Olympian

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